The present invention relates to filling an order in a warehouse or other inventory sensitive area. In particular, the present invention relates to a radio frequency identification system used in a warehouse to register items as they are placed on a pallet and to reflect those items on the order.
In a typical warehouse, orders are constantly being filled in response to new orders being generated. As employees fill an order in the warehouse they must move around the warehouse and obtain each item on the order. Furthermore, the employees must know where each item is in the warehouse. The employees load each item of the order on a pallet or other device, and then deduct the item from the order manually. This manual loading and deduction from an order can allow for errors to occur in loading and filling the order. Furthermore, employees can claim to have loaded an item when in fact it has not been loaded. To combat this problem many warehouses have moved to using radio frequency tags or bar codes to track the movement of items in the warehouse.
With a wide range of capabilities, RF (radio frequency) tags are a growing area in tracking technology. RF identification (RFID) is used for theft control tags, production tracking tags, asset management, product tracking, and other uses. Unlike barcodes, RF tags can be read through almost 2 inches (5 cm) of packaging and are unaffected by moisture and heat making them highly effective in manufacturing and distribution environments. RF tags enable automatic identification with no physical contact. Depending on the specific type of RF tag employed, the read range extends from a few inches to hundreds of feet.
In general terms, RFID is a means of identifying a person or object using a radio frequency transmission, typically 125 kHz, 13.56 MHz or 800-900 MHz. RFID has been extensively used in applications such as toll collection, access control, ticketing, and car immobilization devices (also called immobilizers). In recent years, the technology has received increased attention due to a confluence of actions including technology advancement, heightened security concerns, supply chain automation, and a continuing emphasis on cost control within industrial systems.
The AIDC (Automatic Identification Data Capture) industry is moving rapidly towards the use of RFID in a number of high-value and high-volume market segments. The primary benefit of RFID tags over barcodes is their ease of use and reliability. RFID tags can be read or written at distances up to several feet, while in motion, in any orientation, regardless of dirt or smudges, and through intervening objects. Perhaps most significant is the fact that many RFID tags can be read at once automatically, while barcodes have to be scanned manually, one by one.
An RF tag will only communicate when it is in range of a read/write device (a transceiver, a transmitter/receiver, or a reader) and can be accessed at anytime. RF tags are durable and have a long life span, no battery requirement, and large data memory capacity. RF Tags are available in a variety of different shapes and sizes. Due to their versatility, they can be placed in many different types of casing such as plastic cards, stickers, wristbands, coins, labels, etc. Examples include animal tracking tags, inserted beneath the skin. These tags can be as small as a pencil lead in diameter and one-half inch in length. RF tags can be screw-shaped inserted to identify trees or wooden items, or credit-card shaped for use in access applications. Anti-theft hard plastic tags attached to merchandise in stores can be supplemented as RF tags. In addition, heavy-duty 5-by 4-by 2-inch rectangular transponders can be used to track intermodal containers or heavy machinery, trucks, and railroad cars for maintenance and tracking applications.
In construction an RFID tag has a microchip attached to an antenna. RFID tags are developed using a frequency according to the needs of the system including read range and the environment in which the tag will be read. Tags are either active or passive.
Active RF tags are powered by an internal battery and are typically read/write devices. Active RF tags are more expensive and larger than passive RF tags. However, they are also more powerful and have a greater read range. Passive RF tags are powered by the field generated by the reader. Passive tags are typically much lighter than active tags, less expensive, and offer a virtually unlimited operational lifetime. However they have shorter read ranges and require a higher-powered reader than active tags.
An RFID reader, usually connected to a Personal Computer, serves the same purpose as a barcode scanner. It can also be battery-powered to allow mobile transactions with RFID tags. The RFID reader handles the communication between the Information System and the RFID tag.
An RFID antenna connected to the RFID reader, can be of various sizes and structures, depending on the communication distance required for a given system's performance. The antenna activates the RFID tag and transfers data by emitting wireless pulses.
An RFID station is made up of an RFID reader and an antenna. It can read information stored into the RFID tag and also update the RFID tag with new information. It generally holds application software specifically designed for the required task. RFID stations may be mounted in arrays around transfer points in industrial processes to automatically track assets as they are moving through the process.
However, the use of RF tags in warehouses has not solved the problems of ensuring that the proper items have been loaded on a, pallet to fill an order, or determine whether extra items have been placed on the pallet.